Improvement in processes and apparatus for the manufacture of paper-pulp



UNITED STATES PATENT CFFIOR.

HARRISON R. MEROH, or TROY, N. Y.

IMPROVEMENT IN PROCESSES AND APPARATUS FOR THE NTANUFAGTURE 0FPAPER-PULP.

To all whom Iit may concern:

Be it known that I, HARRISON B. MREcH, formerly of Fort Edward,Washington county, but at present a resident of Troy, in the county ofRensselaer and in the State of New York, have invented a new and usefulImprovementin the Manufacture of Paper-Pulp; and I do hereby declarethat the following is a full, clear, and

` exact description thereof, reference being had to the accompanyingdrawing making a part of this specification, and in which Figure lrepresents a central vertical section of my invention, showing thecirculation of the stock in process of reduction, and Fig. 2 anelevation of the same.

My invention relates to a ma chine for the manufacture of paper-pulp inwhich a complete reduction of the stock takes place, the boiling,grinding, and maceration being accomplished at the same time, and inwhich the process of bleaching can be advantageously effected, and itconsists in certain mechanical combinations and chemical processes, asmore specifically set forth 'in the following specification and claims.

A in the drawing represents a cylindrical upright boiler, into whichstraw, grass, wood-shavings, or other fibrous substance to be reduced topulp is introduced through the man-hole a at the top of the boiler. Thisboiler is provided with a revolving distributing-disk, b, about half thediameter of the boiler, and an agitator, c, near its top and bottom,respectively, both of which are attached to and revolve with the shaftd. Steam is introduced into the boiler by means of the pipe f. B is thegrinding-machine, preferably made as shown, into which the stock entersfrom the boiler through the pipe O1. This machine consists of arevolving cylinder, placed horizontally, and tapering from its center insuch a manner as to produce a figure in the form of two cones joined attheir base. The outer surface of this double-cone cylinder forms one ofthe grindingsurfaces, the other grinding-surface being upon the innerside of the casing, which incloses said cylinder and conforms to itsshape. The distance between said grinding-surfaces corresponds relyatively to the thickness of the packing introduced at the joint of thetwo cones forming the casing referred to. The inner double-cone cylinderis attached to the shaft E, which passes through sniffing-boxes e e ateach end of the Casing, and is driven by the main pulley G. C

represents a pipe which passes through the outer cylinder or casin gnear the end opposite to which the pipe G1 enters, and passes upalongside of and enters the top of the boiler A. This pipe is used toconduct the stock, after it has passed through the grinding-machine,back into the boiler, to be reboiled and reground, or to the pipe C2,through which it is conducted into vats. The circulation through thispipe is produced by a fan, as shown, or other pump, D, which is operatedby a belt which passes over pulley H upon shaft E. This shaft also has apulley, .I, from which a belt passes to the pulley upon shaft F, whichconnects with and turns, by means of gears, the shaft d, to which areattached the distributing-disk and agitator within the boiler. Insteadof the pulley I a swivel-joint, m, and screw, ,will usually be attachedto the shaft E, by means of which the inner rotating conic cylinder maybe adjusted and the grinding regulated. The shaft F will then have otherconnections.

The operation is as follows: The straw or wood to be reduced to pulp,after having been cut into proper lengths, (about one in ch,) isintroduced i11- to the boiler A through the man-hole t until it reachesto within a few inches of the disk b. The boiler is then filled to aboutthe same height with a weak solution of pure caustic alkali (aboutBaume) or other sol/vent, such as a clear liquor made by boiling sulphurand lime together and allowing it to settle. Steam is then admittedthrough the pipe f, and the mass preferably boiled for two hours, moreor less, before the grinding process is commenced. The grindingcylinderis then put in operation, together with the connecting-pulleys andshafts. As this cylinder revolves, the stock which enters at the mouthC:l is carried around between the grind'- ing-surfaces, and thecentrifugal force draws it toward the center, that being the point ofthe greatest diameter of the cylinder. Thence it is drawn by theoperation of the pump to the mouth of the pipe C, through which it isforced and made to re-enter the boiler, falling upon the revolving diskb, from which it is sifted off and deposited evenly in the boiler to beagain boiled and ground as before. This continuous operation goes onuntil the stock is suiiciently reduced, when the valve K is closed andvalve J opened, and the stock in the form of pulp conducted into vats tobe washed and bleached.

In bleaching I prefer to use an apparatus similar to that abovedescribed. In this case a Weak solution of chlorine liquor and chlorinegas is introduced and the machine set in motion, as in the similarapparatus used for reducing. As th e pulp passes through thegrinding-cylinder it is separated into a thin stratum, which enables thechlorine liquor to come in contact with all the fibers and do its Workthoroughly and evenly; also, as the stock is forced back into the boilerit passes through and absorbs all the chlorine gas that may rise to thetop of said boiler, thereby consuming all the bleaching qualitiescontained in the substances used and leaving the fiber in a finecondition to be made into paper. When the pulp is sufficiently bleachedit is forced out through valve J, as in the reducing process beforedescribed.

For making pulp for brown or Manila paper the fibrous substance may beground and boiled in my apparatus in a very weak solution of alkali orsolvent, or simply in soft Water.

What I claim, and desire to secure by Letters Patent, is

l. rEhe combination of the boiler A, doublecone grinder B,circulating-pipe C, and pump D, substantially as and for the purpose setforth.

2. The shaft d, distributing-disk b, and agitator c in combination withthe boiler, as and for the purpose set forth.

3. The circulating-tube C with tube C2 and cocks J and K, as described.

4. rlhe process, herein described, of reducing straw, Wood, or otherfibrous substance to pulp for the manufacture of paper, the sameconsisting in boiling and grinding said substances in a Weak solution ofcaustic alkali of about strength Baume, substantially as described.

HARRISON B. MEECH.

Witnesses:

D. E. SoMEs, F. (j. Somis.

